my buttons works after running the file at least twice (VI is attached)

[rihhs]

hello guys as you can see in the VI  my log in button doesn't work until i press it and run the vi  and generate file button has the same problem so anyone help please 

[PeterFoerster]

My first guess is that your VISA loop is blocking the execution of the big loop. As long as that runs continuously, you're still stuck in the first iteration of the big loop.

I'm pretty sure that your architecture will give you many more of these issues. I recommend looking at the State Machine design pattern, which will solve most of these problems. Also, look at Buttons and how to add images to them.